The medical field of interventional neuroradiology, includes procedures for the treatment of a localized abnormal wall of a vascular structure, such as arteriovenous fistulae and intracranial aneurysms in a vein, artery or vessel. These procedures are delicate, complex and essential to mitigate potential life-threatening fistulae and aneurysms. More specifically, an arteriovenous fistula is basically an opening between the walls of a closely adjacent vein and artery, resulting in a diversion of blood flow from the higher pressure artery to the lower pressure vein. The flow of blood thus diverted, does not reach portions of the body downstream of the fistula.
An aneurysm is basically a ballooning of a blood vessel at an abnormal wall portion of the vessel which is stretched or distended into a shape referred to as a "sac". An intracranial aneurysm is such a ballooning of a vessel in the brain which could result in loss of brain function or death.
Current methods of treating these localized abnormal wall portions of the vascular structure include packing the abnormal wall of the vascular structure with detachable latex or silicone balloons or electrically detachable platinum coils. In the case of intracerebral aneurysms, the placement of any material (balloon, coil) into the thin-walled aneurysm sac has been known to cause catastrophic rupture of the aneurysm, either by direct perforation, or due to changes in the pressure/flow dynamics during manipulation of the aneurysm. In treating large aneurysms, multiple balloons/coils are needed, with resultant intraaneurysmal blood clot formation. This clot may either: 1) lyse, causing reappearance of the aneurysm with new risk of hemorrhage; or 2) fragment, with clot emboli causing varying degrees of cerebral ischemia, including devastating cerebral infarction.
In the case of carotid-cavernous fistulae, difficulties may arise if the vascular structure is too small to accept a balloon or coil delivery catheter. If the opening is large, the balloon/coil may "herniate" into the artery, resulting in stenosis/occlusion of the internal carotid artery or of one or more of its branches.
Because of these potentially disastrous complications, these procedures are technically difficult, and may be performed only by highly trained individuals.
Metallic stents are not favored for use in vessels and ducts because they rust and are not effective.
Therefore, it is desirable to have a new method, and an apparatus for use with the method, to treat a localized, abnormal wall of a vascular structure.
Among the objects of the invention are to provide a method of using a hydrogel material as an implanted intravascular device for the treatment of certain vascular abnormalities, such as aneurysms, fistulae, or tears of a vessel wall; a method for the delivery, placement and implantation of the device using a fluoroscopically guided catheter via the percutaneous puncture of an access vessel; and a kit containing essential apparatus required to practice the methods, to thereby significantly improve treatment of vascular abnormalities.